Air cooling systems for rotary mechanisms



April 27, 1965 HANNS-DIETER PASCHKE AIR COOLING SYSTEM FOR ROTARYMECHANISMS 3 Sheets-Sheet 1 Filed May 31. 1961 No -wm IN V EN TOR.HANNs-D/ETER PAscf/KE ATTORNEYS.

HANNs-DIETER PAscHKE 3,180,323 AR COOLING SYSTEM FOR ROTARY MECHAISMSApril 27, 1965 Fild May 31, 1961 3 Sheets-Sheet 2 INVENTOR HANNs-D/ETERPASCHKE BY WW, rf/903e( ATTORNEYS.

*April 27, 1965 HANNs-DIETER PAscHKE 3,180,323

AIR COOLING SYSTEM FOR ROTARY MECHANISMS Filed May 51. 1961 3Sheets-Sheet 5 INVENTOR.' HA NNs-D/ETE/e PAscHKE yWiM/@w au UnitedStates Patent O 3,180,323 AIR COLING SYSTEMS FR ROTARY MECHANISMSHanns-Dieter Paschke, Neckarsulm, Germany, assigner to NSU MotorenwerlreAktiengesellschaft, Neckarsulm, and Wankel G.m.h.H., Lindau (Bodensee),Germany Filed May 31, 1961, Ser. No. 113,918

Claims priority, application Germany, .lune 1, 1969,

z Claims. (in. 12s-s) The present invention relates to means for coolingrotary mechanisms, and more particularly to an air cooling system forthe inner body or rotor of such mechanisms.

Although this invention is applicable to and useful in almost any typeof rotary mechanism which presents a cooling requirement, such ascombustion engines, iiuid motors, fluid pumps, compressors, and thelike, it is particularly useful in rotary combustion engines. Tosimplify and clarify the explanation of the invention, the descrip. tionwhich follows will, for the most part, be restricted to the use of theinvention in a rotary combustion engine. It will be apparent from thedescription, that with slight modifications which would be obvious to aperson skilled in the art, the invention is equally applicable to othertypes of rotary mechanisms.

The present invention is particularly useful in rotary mechanisms of thetype that comprise an outer body having an axis, axially-spaced endWalls, and a peripheral wall interconnecting the end walls. In suchrotary mechanisms the inner surfaces of the peripheral wall and endwalls form a cavity, and the mechanism also includes an inner body orrotor that is mounted Within the cavity between its end walls. l

The axis of the inner body or rotor is eccentric from and parallel tothe axis of the cavity of the outer body. The rotor has axially-spacedend faces disposed adjacent to the end walls of the outer body and aplurality of circumferentially-spaced apex portions. The rotor isrotatable relative to the outer body, and its apex protionssubstantially continuously engage the inner surface of the outer body toform a plurality of working chambers that vary in Volume during engineoperation, as a result of relative rotation between the rotor and outerbody.

The inner surface of the peripheral wall of the outer body has amulti-lobed profile that is preferably an epitrochoid and the number of'lobes of this epitrochoid is one less than the number of apex portionsof the inner body or rotor.

By suitable arrangement of ports, such rotary mechanisms may be used asfluid motors, compressors, fluid pumps, or internal combustion engines.This invention is of particular importance when employed with a rotarymechanism that is designed for use as a rotary combustion engine, and,accordingly, will be described in combination with such an engine. Asthe description proceeds, however, it will be apparent that theinvention is not llimited to this specific application. j

When the rotary mechanism is designed for use as a -rotary combustionengine, such engines also include an intake passage means foradministering a fuel-air mixture to the variable volume workingchambers,an exhaust passage means communicating with the working chambers,

and suitable ignition means. During engine operation the workingchambers of `the lengine undergo. a cycleV 3,180,323 Patented Apr. 27,i965 ice an .engine could obviously also be operated as a diesel engine.

For efficient operation of the engine, its working charnbers should besealed, and therefore an effective seal is provided between each rotorapex portion and the inner surface of the peripheral wall of the outerbody, as wellas between the end faces of the rotor and the innersurfaces of the end walls of the outer body.

.Between the apex portions of its outer surface the rotor has a contourthat permits its rotation relative to the outer body free of mechanicalinterference with the multi-lobed inner surface of the outer body. Themaximum profile which the outer surface of the rotor can have betweenits apex portions and still be free to rotate without interference isknown as the inner envelope of the multi-lobed inner surface, and theprofile of the rotor that is illustrated in the accompanying drawings.approximates this inner envelope.

For purposes of illustration, the following description will be relatedto the present preferred embodiment of the engine in which the innersurface of the outer body is basically a two-lobed epitrochoid, and inwhich the rotor or inner body has three apex portions and is generallytriangular in cross-section but has curved or arcuate' sides.

It is not intended that the invention be limited, however, to the formin which the inner surface of the outer body approximates a two-lobedepitrochoid and the inner body or rotor has only three apex portions. Inother embodiments of the invention the inner surface of the outer bodymay have a different plural number of lobes with a rotor having one moreapex portion than the inner surface of the outer body has lobes.

In a rotary combustion engine of the type described above, as the rotorrotates relative to the outer body, each of its three working faces goesthrough all four phases of the cycle of operation in succession, i.e.,intake, compression, expansion, and exhaust. The total heat input toeach face of the rotor during the complete cycle of operation can besubstantially high, and this is especially true when the engine isoperating at a high number of revolutions per minute. v

It has been found desirable t-o use a rotor fabricated from a lightweight metal alloy in many applications of the rotary combustion engine.A light weight metal alloy, such as an aluminum alloy, provides theimportant benetits and ,advantagesof ensuring a great saving of weightin the principal moving parts of the engine, and also provides a rotorhaving high thermal conductivity. The latter characteristic isparticularly beneficial in preventing the formation of hot spots withinthe rotor, while the former characteristic greatly reduces energy lossesthe result from inertia forces of the rotor.

A rotor constructed of a lightweight metal alloy, howevery, demandsadequate and efficient cooling, as such alloys will fail fromoverheating at a considerably lower temperature than a material, suchas, cast iron or steel. Accordingly, although the present invention isnot limited to use with light weight metal alloy rotors, it isparticularly useful when used with such rotors.

lIn accordance with the present invention, means are provided forcooling the rotor of a rotary combustion engine during operation, ormore particularly, means are provided for cooling the rotor, withincidental cooling of the outer body, by passing a stream of air orother gaseous medium through the rotor.

It is a primary object'of this invention to provide a` of a rotarymechacool the rotor and thereby eliminates the problem of preventing theescape of coolant liquid along the end of the rotor into the Workingchambers of the engine and also eliminates the energy losses that resultfrom churning and turbulence of cooling liquid within the rotor cavitythat result from changing -accelerations exerted on the rotor duringoperation of the engine. The energy losses due to churning andturbulence of a liquid coolant,1 if not carefully controlled can cause aserious decrease in the eiciency of the engine. Most liquid coolingsystems that have been previously proposed for cooling the rotors ofrotary mechanisms provide for supply of the cooling liquid to the rotorand its return from the rotor by Way of the eccentric or the end wallsof the outer body, and these liquid cooling systems for the rotor havegenerally presented a problem in devising a means to prevent the escapeof the cooling liquid along the end face of the rotor into the workingchambers of the engine; the present invention overcomes this problem.

Another object of this invention is to provide a novel air coolingsystem for the rotor of a rotary mechanism that permits the usc of afuel, air, and lubricant mixture as the coolant for the rotor, as Wellas for the combustible fuel-air mixture that comprises the charge forthe engine and the lubricant for the bearings and the gears of theengine. Use of the cooling system of this invention permits theelimination of an oil seal on the end faces of the rotor radially inwardfrom the gas seal.

Another object of this invention is to provide a novel air coolingsystem for the rotor of a rotary mechanism that uses the cooling air asthe air supply for the fuel-air mixture that forms the combustiblecharge of the engine, when a fuel injection type engine is used. It isalso an object of this invention to permit the use of the cooling air asa supply for scavenging air to be used to scavenge the Working chambersof the engine in cooperation with the exhaust port.

Another object of this invention is to provide a novel air coolingsystem for the rotor of a rotary mechanism that uses the air-fuelmixture that forms the combustible charge for the engine as the coolingair for the rotor and obtains additional cooling effect throughvaporization of the entrained fuel particles as they come near or intocontact with the hot walls of the rotor cavity.

Another object of this invention is to provide a novel air coolingsystem for the rotor of a rotary mechanism that will draw lubricantthrough passages provided for this purpose from the lubricant that isfed to the eccentric and shaft bearings by suction of the cooling airpassing through the rotor and will deposit this air entrained lubricanton the inner surfaces of the outer body to provide lubrication for theapex seals and side gas seals of the rotor as they move into slidingengagement with the inner surface of the outer body.

Another object of this invention'is to provide a novel air-coolingsystem for the rotor of a rotary mechanism that permits the use of atleast one ilywheel of the mechanism as the pressure-fan to aid inpushing cooling air through the rotor and that in some embodiments ofthe invention permit the use of a second flywheel as a suction fan toaid the passage of the cooling air to the rotor by providing a suctionforce at its exit from the rotor.

Another object of this invention is to provide a novel air coolingsystem for the rotor of a rotary mechanism that utilizes the negativepressure in a working chamber ofthe mechanism as an aid in drawingcooling air through the rotor.

Another objective of the present invention is to provide a novel aircooling system for the rotor of a rotary mechanism that is sufiicientlyeffective and eiiicient to permit the construction of the rotor fromlight weight metal alloys, such as aluminum, without danger ofoverheating the thermal distortion of the rotor.

Additional objects of this invention are to provide a d novel aircooling system for the rotor of a rotary mechanism that makes the rotorrelatively inexpensive and easy to fabricate, that achieves substantialsavings in weight of the mechanism and particularly the rotor, thatvirtually eliminates the problem of leakage or freezing of the coolingmedium, and that requires very little servicing as compared with aliquid cooling system. Cooling fins may be used on the interior of therotor cavity adjacent to the apex portions of the rotor to preventexcessive heating of the apex portions and possible binding of the apexseals within their slots in the apex portions. The air cooling cavity inthe rotor permits reduction of its Weight without sacrificing itsstrength, and a further advantage of the air cooling system for therotor is that it is the less expensive to manufacture and produce than aliquid cooling system.

To achieve the foregoing objects, and in accordance with its purpose,this invention provides means which, as embodied and broadly described,comprise a rotor having a cavity that is open at least towards one endWall of the outer body, that is passed through by the cooling medium,and that communicates with a cooling air supply port arranged in atleast one end wall of the outer body in that region of the inner surfaceof the end Wall that is continuously covered by the rotor duringrotation of the rotor relative to the outer body.

When air is used as a cooling medium in this invention, it isadvantageous to provide an annular chamber in each end Wall thatcommunicates with the cavity in the rotor through large openings in therotor end faces. The annular chamber in one end wall serves as adelivery channel for supplying air to the rotor cavity. The annularchamber in the other end wall of the outer body, in one embodiment ofthe invention, serves as a collecting channel for collecting the airfrom the rotor cavity and delivering it to an appropriate transferpassage for use as the combustible charge, part of the combustiblecharge, or as scavenging air.

In another embodiment of the invention the annular chamber in the secondend Wall acts as a collecting channel for exhausting the cooling airfrom the rotor cavity so that the cooling air passes through the rotorcavity but is not further used by the engine after it has passed throughthe cavity.

This invention is especially advantageous as a cooling Vsystem when thecomplete fuel-air mixture that forms the combustible charge is used asthe cooling medium. When this is done, an additional cooling effect isobtained by removal of the latent heat of vaporization by the vaporizingof fuel particles entrained in the fuel-air mixture as they approach orcome into contact with the hot Walls of the rotor cavity.

When the fuel-air mixture is used as a cooling medium in this inventionan intake means is provided in one end wall of the outer body and atransfer passage is provided in the other end Wall. The intake passagemeans communicates with the delivery channel, referred to above, and thetransfer passage communicates with the collecting channel, also referredto above. The opening and closing of the mouth of the transfer passagethat opens into the Working chamber of the engine is controlled by theperipheral edge of the rotor.

It is also possible to provide intake passage means in one end wall anda transfer passage in each end wall; one transfer passage communicatingwith the collecting channel, and the other transfer ypassagecommunicating with the delivery channel. The same arrangement can alsobe used in engines using fuel injection to supply the combustion air, orfor use to provide-scavenging air only Where a scavenging of the workingchambers is desired. When scavenging only is desired, the transferpassage is located so that it is open toa working chamber of the engineduring the exhaust phase.

A lubricant may be added to the cooling medium to obtain lubrication ofthese parts of the engine that engage each other in sliding contact,especially the apex seals and the side gas seals carried by the rotorthat are in sliding engagement with the inner surface of the outer body.Lubricant entrained in the cooling air will condense on the innersurfaces of the outer body in sufficient quantity to provide the desiredlubrication of the rotor seals.

The bearings may also be lubricated, and especially the bearings thatsupport the rotor on the eccentric and the shaft bearings by providingbores that extend from the channels or cavities traversed by the coolingmedium to the rotor and shaft bearings. The cooling medium with itsentrained lubricant is supplied to the bearings through these bores. Thelubrication of these bearings can be improved by providing collectingpockets within the plane of the inner surfaces of the end walls belowthe intake passage means and the transfer passage; the bores extend fromthese collecting pockets and the collecting pockets receive lubricantthat has condensed on the inner surfaces of the end walls as it isscraped off the end Walls by the gas side seals of the rotor.

If entrainment of a lubricant in the cooling medium is not desired, thelubrication of the bearings can be accomplished in the usual way bysupplying a lubricant through passages bored in the eccentric shaft.When this arrangement is used, however, it is also possible to obtain alubrication of the rotor seals as they slide in engagement with theinner surface of the outer body by continuing to provide the bores thatextend from the bearings to the channels or cavities of the rotor andthe cavities of the outer body that are traversed by the cooling medium.Small amounts of lubricant are admixed or entrained in the coolingmedium because of the suction effect that the cooling medium creates asit passes over the outlets of these bores.

A blower can be mounted upon the eccentric shaft in front of the outerorice that feeds to the delivery channel to increase the mass and rateof flow of the cooling medium through the rotor cavity. This blower canbe used as a supercharger if the cooling medium is a fuel-air mixturefor combustion air, or as a scavenging fan if the cooling medium isscavenging air. In one embodiment of this invention in which cooling airenters through one end wall of the outer body and leaves through theother end wall after passing through the rotor cavity without beingutilized in the working chambers of the engine, a blower can be arrangedon each side of the outer body, one designed as a pressure fan, and theother as a suction fan.

The fan wheels are preferably also formed as fly-wheels and includecounter-Weights to balance the rotor and eccentric. Suitable guide vanesmay be provided between the fan wheel and the channels for directing thecooling air inthe desired direction.

Since the'seals at the apex portions of the rotor must be movablerelative to the rotor to function properly it is important that the apexportions of the rotor be cooled well enough to prevent binding of theseals in the apex portions. This invention permits the desired coolingeffect to be obtained by providing cooling ns within the rotor cavity inthe region of the apex portion such that the fins are swept by thegaseous cooling medium as it passes through the rotor cavity and heat israpidly removed from the rotor apex portions.

Additional objects and advantages of the invention will be set forth inpart inthe description which follows and in part will be obvious fromthe description, or may be learned by practice of the invention, theobjects and advantages being realized and attained by means of theinstrumentalities and combinations particularly pointed outV in theappended claims.

The invention consists Vin the novel parts, constructions, arrangements,combinations, and improvements shown and described.

`The accompanying drawings, which are incorporated in and constitute apart of this specification, illustratel one embodiment of the inventionand together with the description serve to explain the principles of theinvention.

Two embodiments of this invention are shown in the accompanyingdrawings.

Of the drawings:

FIG. l is a central vertical section of the mechanism taken along line1-1 of FIG. 2. FIG. l shows an embodiment of the invention in which thecooling medium, after passing through the rotor cavity is introducedinto the working chambers of the mechanism;

FIG. 2 is a sectional view of the mechanism taken along the line 2 2 ofFIG. 1. The gearing has been omitted from this View for clarity;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. l andshowing the inner orice of the delivery channel that admits the coolingmedium to the rotor cavity;

FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3;

FIG. 5 is a sectional View taken along the lines 5-5 of FIG. 3 showingthe collecting channel and transfer passage for combustion air;

FIG. 6 is a central vertical section of a modified form of thisinvention in which the cooling air is exhausted to the atmosphere afterpassing through the rotor cavity instead of being admitted to one ormore of the working chambers of the mechanism.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory but arenot restrictive of the invention.

Reference will now be made in detail to the present preferred embodimentof this invention, an example of which is illustrated in theaccompanying drawings.

In accordance with the invention, a rotary combustion engine and a meansfor air cooling its rotor or inner body are provided. As embodied, andas shown in FIGS. 1, 2, and 6, the present preferred embodiment of theinvention includes a rotary combustion engine comprising a generallytriangular rotor 10 having arcuate sides which is eccentricallysupported for rotation within an outer body 12.

Although in the illustrative embodiment shown in the drawings the outerbody 12 is fixed or stationary, a practical and useful form of theinvention may be constructed in which both the outer body and rotor arerotary; in this latter form of the invention the power shaft is drivendirectly by rotation of the outer body and the inner body or rotorrotates relative to the outer body.

As shown in FIGS. l and 2, and as here preferably embodied, the rotorltlrotates on an axis 14 that is eccentric frorn and parallel to theaxis 16 of the curved inner surface of the outer body 12. The distancebetween the axes 14 and I6 is equal to the eccentricity of the engineand is designated e in the drawings. The curved inner surface 13 of theouter body 12 has basically the form of an epitrochoid in geometricshape and includes two arched lobe-defining portions or lobes.

. As embodied, the generally triangular shape Vof the rotor 10corresponds in its conguration to the inner envelope o1I the maximumprofile of the rotor which will permit interference free rotation of therotor 10 Within the outer body 12.

In the form of the invention illustrated, the outer body 12 comprises aperipheral wal-l 20 that has for its inner surface the curved innersurface 18, and a pair of axiallyspaced end walls 22 and 24 that aredisposed on opposite sides of the peripheral wall 20.

v The end walls 22 and 24 support a shaft 26, the geometric center ofwhich is coincident with the axis 16 of the outer body 12. This shaft 26is supported for rotation by the end Walls 22 and24 on bearings 28. Ashaft eccentric 30 is rigidly attached to or forms an integral part ofthe shaft 26, and the rotor 10 is supported for rotation or rotativelymounted upon the shaft eccentric 30 by rotor bearings 32.

As shown in FIGS. l and 6, an internally-toothed or ring gear 34 isrigidly attached to the rotor 1t). The ring gear 34 is in mesh with anexternally-toothed gear or pinion 36 that is rigidly attached to thestationary end wall 24 of the outer body 12.

From this construction, it may be observed that the gearing 34 and 36does not drive or impart torque to the shaft 26 but merely serves toindex or register the position of the rotor 10 with respect to the outerbody 12 as the rotor rotates relative to the outer body and removes thepositioning load that would otherwise be placed upon the apex portionsof the rotor 10.

As shown most clearly in FIG. 2, the rotor 10 includes three apexportions 3S that carry radially movable sealing members 4t). The sealingmembers 40 are in substantially continuous gas-sealing engagement withthe inner surface 1S of the outer body 12 as the rotor 1) rotates withinand relative to the outer body 12.

By means of the rotation of the rotor 10 relative to the outer body 12,three variable volume Working chambers 42 are formed between theperipheral working faces 44 of the rotor i and the inner surface I8 ofthe outer body 12. As embodied in FIG. 2, the rotation of the rotorrelative to the outer body is counter-clockwise and is so indicated byan arrow.

A spark plug 46 is mounted in the peripheral wall 2) of the outer body12, and at the appropriate time in the engine cycle, the spark plug 46provides ignition for a compressed combustible mixture which, onexpansion, drives the rotor in the direction of the arrow. As previouslystated, the rotary combustion engine may also be operated as a diesel,and when it is operated as a diesel, the spark plug 46 is not required,since ignition of the fuel is initiated by the temperature reachedthrough high compression of the Working air.

Also as shown in FIG. 2, one lobe of the epitrochoid surface 18 isprovided with an intake port 48, and the other lobe is provided with anexhaust port 50. As the rotor 10 rotates, a fresh charge is drawn intothe appropriate working chamber 42 through the intake port 48. Thischarge is then successively compressed, ignited, expanded, and finallyexhausted through the exhaust port 5).

All four successive phases of the engine cycle: intake, compression,expansion, and exhaust, take place Within each one of the variablevolume working chambers 42 each time the rotor completes one revolutionwithin the outer body, and for each revolution of the rotor, the enginecompletes a cycle.

The working faces 44 of the rotor 10 are provided with cut-out portionsor channels 52 that permit combustion gases to pass freely from one lobeof the epitrochoidal inner surface 18 to the other lobe, when the rotoris at or near the dead center of maximum compression position. Also, adesired compression ratio of the engine may be attained by appropriateproportioning of the volume of the channels 52.

Since the gear ratio between the rotor ring gear 34 and the outer bodygear or pinion 36 is 3:2, each time the rotor It) completes onerevolution about its own axis 14, the shaft 26 rotates three times aboutits axis 16.

In the present preferred embodiment of this invention illustrated in thedrawings, the end walls 22, 24 are provided with bearing flanges 54, 56,respectively, that rotatably support the shaft 26 on bearings 28. Theshaft 26 in turn carries two y wheels, fly wheel 58 adjacent to end wall22, and fly wheel 60 adjacent t0 end wall 24. The y wheels 58 and 60 aresuitably counterweighted to balance the rotor and eccentric, such as,with lightening holes 62 as shown for fly Wheel 60.

Fly wheel 58 is provided with vanes 64 that are canted in a direction tocause them to act as a pressure fan in a direction toward the rotor.

An intake passage means 66 for fresh gases is provided upstream from theily wheel 58. A carburetor (not shown) may optionally be attachedupstream from the intake passage means 66 and would normally be soattached unless fuel injection is to be used with the engine. The intakepassage means, as shown in FIG. l, is formed from the end wall cover 68.

As shown in FIGS. 1 and 3, he bearing flange 54 is provided with ribs 76and supply passages 72 through which the gaseous cooling medium canflow. The ribs 70 may be canted or shaped to act as guide vanes to guidethe gaseous cooling medium in a desired direction.

After flowing through the passages 72 the gaseous cooling medium entersan annular delivery chamber 74 that is open towards the rotor 10 andlies within the region of the inner surface of the end wall 22 that iscontinuously covered by the rotor or bordered by its gas side seals 76as the rotor rotates relative to the outer body.

In accordance with the invention means are provided for the ow of thegaseous cooling medium through the rotor. As embodied, this meanscomprises a cavity 78 Within the rotor that is open towards both endwalls 22, 24. As shown in FIG. 2, this cavity 78 within the rotor islarge and is interrupted only by supporting ribs 80 that support theouter portion of the rotor upon the eccentric 36 through the bearings32.

In accordance with the invention, means are provided for receiving thegaseous cooling medium after it has passed through the cavity of therotor. As embodied, and as shown in FIGS. 1 and 5, this means comprisesan annular collecting chamber 82 that is similar to and is thecounterpart of the annular delivery chamber 74 in the end wall 22. Theannular collecting chamber 82 is formed in the end wall 24 and receivesthe gaseous cooling medium as it leaves the rotor cavity 78. The annularcollecting chamber S2 also lies completely within the region that iscontinuously covered by the rotor and is bordered by its gas side seals76.

In accordance with the invention means are provided for transferring thegaseous cooling medium from the rotor cavity into a working chamber ofthe engine. As embodied, and as shown in FIGS. 2 and 5, this meanscomprises the annular collecting chamber 82 in conjunction With thetransfer passage 84. The upper end of the transfer passage 84 forms theintake port 48 for the engine in the embodiment shown in FIGS. 1 through5. The admission of the gaseous cooling medium to the Working chamber ofthe engine is controlled by the outer periphery of the rotor 10, orworking face 44 in a manner such that the working chamber 42communicates with the rotor cavity 78 only while the working chamber 42ais undergoing the intake phase.

If the engine is of the fuel injection type, the gaseous cooling mediumwill be combustion air, but if the engine is not of the fuel injectontype, then the entire combustible charge constituting the fuel-airmixture will form the gaseous cooling medium and will be introduced intothe working chamber 42a from the transfer passage 84 and intake port 48after having passed through the rotor cavity 78.

In operation, the fresh cooling gases are pulled through the rotorcavity 78 by the negative pressure within the working chamber 42a and bythe pressure fan arrangement of the fan wheel 58. The cooling gasesunder pressure from the blade 64 of the fan wheel 58 flow through thepassages 72 around the guide vanes 70 into the annular delivery chamber74, through the rotor cavity 78, into the annular collecting chamber 82,and from the chamber 82 into the transfer passage 84 through the intakeport 48 and into the working chamber 42a as it undergoes its intakephase. The ow of cooling gas into the working chamber 42a will beinterrupted when the working face 44 of the rotor closes the intake port48, as shown in FIG. 2. Flow into chamber 42a will begin again, however,when the succeeding working face 44 of the rotor uncovers the intakeport.

As shown in FIG. 3, a second transfer passage 86 may be provided in theend wall 22 so that there will then be a transfer passage in both endWalls. The operation of the transfer passage 86 is the same as that forthe transfer passage 84.

As already indicated in the embodiment of FIGS. 1 through 5, either airor a fuel-air mixture may be supplied through the intake passage 66 forflow through the rotor transfer passage 84 (and the transfer passage 86if provided) into the Working chambers (chamber 42a in FIG. 2) forcombustion in this chamber. If only air is so supplied, then instead ofusing this air for combustion purposes, it may alternatively be used tohelp scavenge the Working chambers of exhaust gases. For this latterpurpose the transfer passage 84, and, if provided, the transfer passage86, would be shifted to a position so as to open into the Workingchambers (chamber 42b in FIG. 2) adjacent to the exhaust port 50.

As previously described, the apex seals 40 are radially movable Withintheir mounting grooves in the apex portions 38 of the rotor 10. Inaccordance with the invention means are provided to prevent an excessiveheating of the apex portions 38 that could result in binding the apexseals 40 within their mounting grooves against radial movement. Thismeans provides for intensive cooling of the apex portions and asembodied, comprises a series of cooling fins 92 arranged Within therotor cavity 7S adjacent to the apex portions of the rotor, as shown inFIG. 2. Also as shown in FIG. 2, the cooling ns 92 extend substantiallyin an axial direction across the width of the rotor cavity 78.

In accordance With the invention, a lubricant may be added to thefuel-air mixture or the combustion and scavenging air, respectively, forlubricating both the apex seals 40 and the side gas seals 76. Theserotor seals engage and slide against the inner surfaces of the outerbody continuously during operation of the mechanism and it is importantthat they receive suflicient lubrication to keep friction to a minimum.The desired lubrication can be achieved through inclusion of a lubricantin the cooling; the lubricant is admixed or entrained into the coolinggas as it is fed into the engine through the intake passage means 66.

In accordance with the invention, means may be provided to lubricate therotor bearings 32 and shaft bearing 28 by means of a lubricant entrainedWith the cooling gas. As embodied, the means comprises passage 94 inbearing flange 54, passage 96 in bearing ange 56, and passage 98 in theeccentric 30. These passages extend to the shaft and rotor bearings fromtheir respective annular chambers y74 and 82 and from the rotor cavity78.

By means of these passages 94, 96, 98, the cooling gas with itsentrained lubricant can be delivered to the respective bearings 28, 32.The lubrication of the bearings 28, 32 can be reinforced by theprovision of collection pockets 100, 102, 104 at the bearing anges 54,56, and eccentric 30, respectively. The pockets 100, 102 in the bearingflanges 54, S6 are arranged in the plane of the inner surface of the endWalls 22, 24. Radially inside of the annular chambers 74 and 82 so thatthese pockets collect the lubricant scraped off of these inner surfacesby the rotor and its gas side seals 76. The collecting pockets directthe lubricant into the passages 94, 96, 98 and from thence to thebearings.

In accordance with the invention, a lubricant can be omitted from thecooling gas and the lubrication of the shaft bearings 28 and rotorbearings 32 can be achieved by means of axial 106 and radial 188passages within the eccentric 30 in the shaft 26, as shown in FIG. 1.

When this type of lubrication is used, lubrication of the rotor seals isachieved by retaining the passages 94, 96, 98. The suction effect of thecooling gas passing through the rotor cavity 78 is sufficient to drawlubricant l@ up through the passages 94, 96, 98 and admix or entrainthis lubricant with the cooling gas. Suiicient of the lubricant thencondenses on the inner surfaces of the outer body to provide adequatelubrication of the rotor seals.

In accordance with this invention, an alternative embodiment of theinvention is shown in FIG. 6. To simplify and clarify the description ofthis alternative embodiment of the invention, those parts of theembodiment of FIG. 6 that correspond to similar or almost identicalparts of the embodiment shown in FIGS. 1 through 5 Will be designated bythe same reference numerals, but the reference numerals will be primed.

The embodiment of the invention shown in FIG. 6 is similar in its designto the embodiment shown in FIGS. 1 through 5, with the one outstandingdifference, that instead of using a fuel-air mixture, or combustion air,or combustion air and scavenging air for the cooling gas, simple coolingair is used with no purpose other than that of cooling the rotor 10 andwhatever incidental cooling of the outer body 12' may be obtained in thecourse of flowing cooling air through the rotor.

In accordance with the invention, the transfer passage 84 (and of coursealso the transfer passages 86) are omitted from the construction. Thebearing flange 56 of FIG. 6 is modified from the bearing flange 56 ofFIG. 1 in that it is ribbed like the bearing flange 54 of FIG. 1 andincludes outlet passages 110 that correspond to the inlet passages '72of FIGS. 1 and 3. The outlet passages extend from the annular collectingchamber 82 that, similar to the annular collecting chamber 82 in FIG. 1,is arranged in the end Wall 24 in that region of the inner surface ofthe end wall that is continuously covered by the rotor and is radiallyinward from the path of travel of the gas side seal 76 of the rotor.

In accordance with the invention, the fly Wheel 66 is designed as asuction fan with vanes 112 canted or oriented to provide a suction forceto assist the pressure force provided by fan Wheel 58' to ow the coolinggas through the rotor cavity 78'. The outlet passages 11) in theembodiment of FIG. 6 may be provided with guide vanes through theshaping or canting of the ribs 114 of the bearing flange 56 similar tothe manner in which the guide vanes 70 of the bearing fiange 54 in FIG.1 were shaped to aid the flow of the cooling gas.

The intake of the fuel-air mixture or the combustion air for theembodiment shown in FIG. 6 is effected in the ordinary manner by meansof a suitably arranged intake port and exhaust port. In this embodimentboth a peripheral intake port and exhaust port are preferably used. If aside intake port Were to be used, the intake area would have to be quitesmall as compared to conventional side intake port rotary combustionengines. Because of the large opening that leads into the rotor cavity'78 in this invention, unless a side intake port is made quite smallthecooling air and the charge in the combustion chamber would mix; thiswould make the engine inoperative. Accordingly, with the embodiment ofFIG. 6 the use of an intake port in the peripheral Wall is preferred toa side intake port. Similarly, the exhaust port is preferably alsolocated in the peripheral Wall.

As best shown in FIGS. 1 and 3 the eccentric Sti in this inventionincludes a half-moon opening in its end faces that provides a cavity 31directly through the eccentric. This cavity 31 permits the cooling gasto flow through the eccentric as Well as through the rotor cavities 78.The cavity 31 also makes the eccentric lighter in Weight and contributesto the overall balanceV of theV engine. A strengthening rib 33 isprovided in the center of the eccentric cavity 31.

This invention provides the means for achieving an efcient and effectiveair cooling system for a rotary combustion engine or other type ofrotary mechanism. By using the means of the present invention to achievean air cooling system, it is possible to effect significant economies inthe manufacture and operation of rotary mechanisms. The cooling cavitiesin the rotor and eccentric lighten these parts and reduce inertia losseswithout the accompanying disadvantages that are introduced when a liquidcoolant is used. When a liquid is directed into the rotor to cool it,problems of churning and turbulence of the liquid are introduced as wellas an inertia loss caused by the weight of the liquid itself. l

The air cooling system of the present invention is relatively simple,easy, and economical to construct and trouble free in operation. Unlikea liquid cooling system, the air cooling system provided by thisinvention avoids any necessity for a multiplicity of fittings, conduits,channels, and passages for transferring cooling liquid from one point toanother in the system with consequent danger of leakage, breakage, andfailure through loss of cooling liquid.

Another advantage of the present invention is that the cooling air flowmay be routed through the outer body 12, 12 of the engine in a mannersuch that the cooling air will cool the outer body as well as the rotorin the course of its passage through the engine. The arrangement of aircooling passages within the outer body to achieve this object presentsno unusually difficult problems to be overcome and is considered to bewithin the skill of a person trained in the art.

From the foregoing detailed description of the present preferredembodiment, it is apparent that this particular embodiment is restrictedto mechanisms in which the outer bodies are stationary and the rotorsand eccentrics are rotary, but it is no intended to limit the scope ofthe invention to such a mechanism. lt is apparent that with mechanicalchanges that would be obvious to a person skilled in the art,alternative embodiments using the principles of this invention could beconstructed in which both the outer body and rotor are rotary and theeccentric is stationary with a power shaft taken olf the outer body.

Accordingly, this invention in its broader aspects is not limited to thespecific mechanisms shown and described, but also includes within thescope of the accompanying claims any departures made from suchmechanisms which do not sacrice its chief advantages.

What is claimed is:

1. In a rotary mechanism having a hollow outer body comprising twospaced-apart end walls and a peripheral wall interconnecting the endwalls, a rotatable shaft journaled in the end walls on the aXis of theouter body and having an eccentric portion disposed within the outerbody, and a rotor disposed within the outer body Ihaving a plurality ofportions sweeping the inner surface of the peripheral wall in sealingrelation therewith, the rotor being mounted on the eccentric forrotation relative to the outer body and to the eccentric; theimprovement of a cooling system comprising the rotor having an internalcavity for the ow of a gaseous cooling medium through the rotor, thecavity being open toward at least one of the end Walls, the end walladjacent to the rotor opening having a port for supplying cooling mediumtherethrough to the rotor opening, the port being located in thatportion of the end wall which is at all rotor positions radially inwardof the outer periphery of the rotor, the rotor being mounted on theeccentric on rotor bearings to permit relative rotation between theeccentric and the rotor, the shaft being supported by the end walls ofthe outer body on shaft bearings, the mechanism including passagesconnecting the rotor cavity with the shaft bearings and the rotorbearings, whereby lubricant admixed with the cooling gas can be carriedby the cooling gas to the bearings through said passages.

2. The invention as dened in claim 1, in which the rotary mechanism hascollecting pockets adjacent to the rotor cavity ends of the passages andin the plane of the inner surface of the end wall to receive lubricantscraped off the end walls by the movement of the rotor adjacent to theend Walls during rotation of the rotor relative to the outer body.

References Cited by the Examiner UNITED STATES PATENTS 851,962 4/07Prossen 123--8 1,065,962 7/13 Newburg 123--8 1,846,298 2/32 Alcznauer123-41.17 2,175,265 10/39 Johnson 123-8 2,808,813 10/57 Lindhagen et al12S-8 2,939,438 6/60 Bush 123-8 2,956,554 10/60 Froede et al. 123-82,988,065 6/61 Wankel et al 123-8 2,990,820 7/61 Saijo 123-44 X FORElGNPATENTS 570,641 2/59 Canada. 565,812 4/58 Belgium.

JOSEPH H. BRANSQN, JR., Primary Examiner. RALPH H. BRAUNER, Examiner.

1. IN A ROTARY MECHANISM HAVING A HOLLOW OUTER BODY COMPRISING TWOSPACED-APART ENDS WALLS AND A PERIPHERAL WALL INTERCONNECTING THE ENDWALLS, A ROTATABLE SHAFT JOURNALED IN THE END ON THE AXIS OF THE OUTERBODY AND HAVING AN ECCENTRIC PORTION DISPOSED WITHIN THE OUTER BODY, ANDA ROTARY DISPOSED WITHIN THE OUTER BODY HAVING A PLURALITY OF PORTIONSSWEEPING THE INNER SURFACE OF THE PERIPHERAL WALL IN SEALING RELATIONTHEREWITH, THE RATOR BEING MOUNTED ON THE ECCENTRIC FOR ROTATIONRELATIVE TO THE OUTER BODY AND TO THE ECCENTRIC; THE IMPROVEMENT OF ACOOLING SYSTEM COMPRISING THE ROTOR HAVING AN INTERNAL CAVITY FOR THEFLOW OF A GASEOUS COOLING MEDIUM THROUGH THE ROTOR, THE CAVITY BEINGOPEN TOWARD AT LEAST ONE OF THE END WALLS, THE END WALL ADJACENT TO THEROTOR OPENING HAVING A PORT FOR SUPPLYING COOLING MEDIUM THERETHROUGH TOTHE ROTOR OPENING, THE PORT BEING LOCATED IN THAT PORTION OF THE ENDWALL WHICH IS ALL ROTOR POSITIONS RADIALLY INWARD TO THE OUTER PERIPHERYOF THE ROTOR, THE ROTOR BEING MOUNTED ON THE ECCENTRIC ON ROTOR BEARINGSTO PERMIT RELATIVE ROTATION BETWEEN THE ECCENTRIC AND THE ROTOR, THESHAFT BEING SUPPORTED BY THE END WALLS OF THE OUTER BODY ON SHAFTBEARINGS, THE MECHANISM INCLUDING PASSAGES CONNECTING THE ROTOR CAVITYWITH THE SHAFT BEARINGS AND THE ROTOR BEARINGS, WHEREBY LIBRICANTADMIXED WITH THE COOLING GAS CAN BE CARRIED BY COOLING GAS TO THEBEARINGS THROUGH SAID PASSAGES.